GBADoom

GBADoom
General
Author	doomhack
Type	Shooter
Version	2.5
License	Mixed
Last Updated	2023/01/29
Links
Download
Website
Source

GBA Doom is a port of prBoom to the GBA. Comes with a pre-compiled build with the shareware wad embedded.

Build instructions.

Features

• Supports Doom Shareware, Retail, Ultimate and Doom2 IWADS.
• Renderer is largely intact. Z-Depth lighting is gone and there is mip-mapping but it's otherwise complete.
• Monster behaviour is all intact (I.e sound propagation etc).
• Framerate is pretty variable. Simple areas run at ~35fps. Complex areas (Eg: E4M2) chug along at about 10 FPS. It's running around the same as the original GBA Doom1 and Doom2 ports. Doom1 Episodes 1-3 are all completely playable. Episode 4 chugs.
• Sound and music support. Big thanks to BloodShedder for his Chiptune Doom MOD files.

User guide

Cheats

• Chainsaw - L, UP, UP, LEFT, L, SELECT, SELECT, UP
• God mode - UP, UP, DOWN, DOWN, LEFT, LEFT, RIGHT, RIGHT
• Ammo & Keys - L, LEFT, R, RIGHT, SELECT,UP, SELECT, UP
• Ammo - R, R, SELECT,R, SELECT,UP, UP, LEFT
• No Clipping - UP, DOWN, LEFT, RIGHT, UP, DOWN, LEFT, RIGHT
• Invincibility - A, B, L, R, L, R, SELECT, SELECT
• Berserk - B, B, R, UP, A, A, R, B
• Invisibility - A, A, SELECT,B, A, SELECT, L, B
• Auto-map - L, SELECT,R, B, A, R, L, UP
• Lite-Amp Goggles - DOWN,LEFT, R, LEFT, R, L, L, SELECT
• Exit Level - LEFT,R, LEFT, L, B, LEFT, RIGHT, A
• Enemy Rockets (Goldeneye) - A, B, L, R, R, L, B, A
• Toggle FPS counter - A, B, L, UP, DOWN, B, LEFT, LEFT

Mod and conversions

• GBADoom SVN by Kippykip.
• GBAFreeDoom by Devin "RetroGamer02".
• GBA Doom WAD Conversions by Bazooka_Face.
• Chex Quest GBA by Jinroh.

Controls

B - Fire

A - Use, Sprint

D-Pad - Walk

L/R - Strafe

Select - Automap

A+R - Weapon up

A+L - Weapon down

Start - Menu

Screenshots

Compatibility

Plays on most emulators or a real device if you have a flash cart.

Known issues

Demo compatibility is broken.

General optimisation. It is never going to get a perfect 35FPS but there maybe still another 25% left without changing the visual quality/correctness/game behaviour. For reference, the first build ran under the emulator it ran at about 3FPS.

Although it is based on prBoom, most of the engine enhancements (dehacked, limit removing etc) have been reverted back to Vanilla. This is either for memory or performance reasons. Sadly, NUTS.wad and Okuplok are right out.

No multiplayer.

Changelog

2.5

• Remove Invulerabiliy cheat on type-11 floors. (E1M8 ending) With thanks to ez-me.
• Fix sprite render error in low-detail mode where sprites would spill off the right edge of the screen

2.4

• Fix sprites not rendering properly.

2.3

• Fix broken sound in 2.2.

2.2

• Added high detail graphics mode. In this mode sprites are drawn at full resolution and texture mipmapping is removed. There is a modest framerate penalty.
• Various Memory savings. Saved a few kb here and there by using bitfields, factoring out struct members. All of Plutonia with the exception of Map 28 will load and play now on Nightmare.
• Use the original iD Doom Zone memory allocator. This removes some overhead from each memory allocation.
• Minor performance improvements.

2.1

• Add screen wipe effect back in. Backported from here.
• Some fairly minor optimisations. Mainly factoring out division.
• Build with Link time code gen. (-flto).

2.0

• Lots of optimisations. Factored out more division, use reciprocal table, move more code to IWRAM. Offers around a 15-25% improvement in FPS.
• Some memory savings. There's still a couple of levels in Plutonia that won't load, (Map 23 & 28).
• Added framerate display. (Which can be accessed via a cheat. Thanks KipyKip. Why didn't I think of that!?) It replaces your current weapon ammo display and is in 10th's. So 234 = 23.4FPS.
• Fixed cyberdemon and spiderdemon not being drawn at distances over 1280 units.
• Allowed PC build for debugging with MSVC compiler too (Use 32bit. I don't think it works 64bit due to struct alignment).

External links

• GitHub - https://github.com/doomhack/GBADoom
• Doomworld - https://www.doomworld.com/forum/topic/110625-gba-doom-source-port-running-on-game-boy-advance/